Method of and apparatus for cleaning high-pressure boiling apparatus



July-24, 192s. 1,678,089

G. ULLMANN METHOD 0F `ANI) APPARATUS FOR`CLEANING HIGH PRESSURE BOILINGAPPARATUS Filed Aug. 25,1926

Klaren/01" G. Z7!! m a 777/ ,guy/n( Patented July 24, 192s.

UNITED- STATES PATENT OFFICE.

Gus'rAv ULLMANN, or' VIENNA, AUSTRIA.

METHOD 0F AND APPARATUS FOR CLEANING HIGH-PRESSURE BOILING APPARATUS.

Application led August 23, 1926, Serial No. 131,090, and in AustriaAugust 28, 1925.

' VIn the high pressure boilino apparatus employed in industry forpurifying or for dissolving different materlals the pressure must bereleased i. e., a so-called blow-oli:l must be effected rior to thetreatment following on the boiling operation. The pressure has hithertobeen released simply by opening a blow-off valve provided generally inthe upper part of the boiler. This method of operation presents a numberof disadvantages which are hereinafter explained as regards highpressure boiling apparatus employed in the textile industry for cleaningthe raw material.

After the conclusion of theboiling yoperation which usually takes a fewhours, the alkaline solution has absorbed the impurities contained inthetextile materials. During the boiling operation the material is more orless packed together and'a layer of scum or mud like matter consistingof this solution and impurities, collects above the materia-l. VIf theblow-off valve be opened not only doesthe steam produced by thereleaseof the pressure pass off but considerable quantities of the solution arecarried off with it due to the continued evaporation. If the boiler isblown off into the atmosphere these impurities are spread into theimmediate surroundings. The surrounding air is laden with evil smellingand unsanitary particles of alkali and suc-h, and neighbburing vegetablegrowth is destroyed. The blowing off of the hot solution under pressureinto the blow off gutter or the like which is also eected destroys thewalls of the gutter in a short time. Moreover as a result of thelongcontinued evaporation very often too4 much of the solution escapesand the material being cleaned is no longer completely covered by theliquid and air penetrates the fibres soaked with the solution as aresult of which vegetable textile fibres as is Well known are seriouslydamaged. Apart from this the dirtiest mud like yportions of thesolutionimmediately above the material remain in the dome of the boilerand in the subsequent washing generally efected by water flowingdownwardly from the upper end through the boiler such portions are.

carried through the whole contents of the boiler again so that not onlyis the washing out of theboiler rendered ditlicult but the dirt which isdifficult to remove subsequentiy sett-les on the already treated textilebres.

ofi' valve water or other cleaning liquid is introduced into theI boileras aresult of which the scourings are diluted and the mass of scum andmud collected particlularly in the dome portion washed away. By thismethod moreover the duration of the blowing off operation isconsiderably shortened.

The impurities taken up by the solution present the further disadvantagethat in boiling apparatus having pre-heaters the impurities settle inthe tubes of the pre-heater. Experience has shown that the impuritiesadhering to the tube walls of the pre-heater can easily be removed aslong as no cooling has occurred. After the conclusion of the blow-offand after cooling of the pre-heater the impurities adhere so firmly thatthey can no longer be simply washed away and consequently the ,tubes ofsuch pre-heaters have hitherto been gradually reduced in diameter byhard coatin s which settle on them which coatings affect le transfer ofheat and extend the time of treatment. Eventually the tubes have to beremoved and freed from the adhering incrustation by a laborious processwhich gene-rally. seriously damages the tubes.

In accordance with the present invention this disadvantage is alsoavoided by washing the pre-heater directly after the conclusion of` theboiling process i. e., at the same time as the pressure in the boiler isreleased, the solution flowing out of the boiler (which solution isbeing diluted by the cleaningliq-- uid introduced into the boiler) beingpreferably led through the pre-heater and serving for washing thelatter.

The invention includes apparatus for carrying out the new method andalso all methods of using high pressure boiling apparatus in which therelease of the pressure presents similar difficulties to those inapparatus for cleaning textile materials; for example in apparatus fortreating cellulose and the like.

rlwo embodiments of high press re boiling apparatus in accordance withthe invention and suited for cleaning textile fibres are illustrated inthe accompanying drawing.

Figure 1 shows the boiler alone with this improvement and Figure 2 showsthe boiler with a preheater attached. The letters apply to equivalentparts in both figures.

Referring to the drawing a denotes the boiler which in the usual manneris provided wit-h upper and lower perforated sieve plates b and cbetween which the material to be treated is introduced and it may bemade sectional to facilitate removal. To t-he cover d is connected theblow-ofi pipe f which is provided with a valve g and extends into areceiver t. In the domed space z' is located a pipe j formed withperforations distributed over its length and connected by means of apipe k and a three-way cock 'w with a water pressure supply. The pipe isso arranged as not to interfere with the introduction and removal of thematerial to be treated. Water under pressure can also be supplied bymeans of a pipe k2 having a valve to a pipe 0 into which leads thedraw-off pipe p of the receiver h. The water under pressure flowsthrough a nozzle g into the pipe o and in consequence has an ejectoraction on the liquid flowing out of the receiver h. The pipe o. like thedraw ofi' pipe 1' of the boiler a opens into the gutter s. By means of aseparate pipe 104 cold water can be introduced into the container h.

On the conclusion of the boiling or like operation the blow-ofil valve gand the water valve lw are opened, and the dirty upper part of thesolution, therefore, is forced by the water under pressure into thereceiver h and is condensed by the cold Water contained therein. Apartial vacuum is thus produced in the receiver It which vacuumconsiderably accelerates the outflow of the liquid from the boiler. Thiscold water, the pressure of which must always be somewhat greater thanthat within the boiler canbe preheated or may contain admixtures. Thewater flowing into the dome i dilutes the solution therein and washesthe dome thoroughly while at the same timeprotecting the material undertreatment from contact with air. The textile material between theperforated sieve plates b, c, remains full of solution as the waterfiowing from the pipe z' passes off through the pipe f which presents asmaller resistance to the water than the mass of textile material.

The release of the pressure and the blowoff of the boiler requires onlyquite a small part of the time hitherto required for this purpose whileby the dilution of the solution being discharged all the disadvantagesreferred to above are avoided.

After the blow-off the dome z' ofthe boiler in which the greatest partof the impurities had collected, is thoroughly cleaned and inconsequence subsequent washing of the material can be effected with muchless work, in a much shorter time and much more effectively than usual,because the impurities contained in the dome z' are no longer spreadover the Whole mass of material and 'no' longer require to be washed outof suoli maprovided with the pre-heater t in which the.

solution is led in circulation through the boiler a and through thetubes of the preheater t by means of a pump or the like and the pipes fand r. The water under pressure for washing the dome z' passes into theboiler a through the pipe le which is adapted to be closed by a valvela. The receiver i is connected with the tube system arranged in thepre-heater t by a pipe ain which is interposed a valve o. As in theconstruction shown in Fig. 1 the outlet pipe p opens into a branch 0leading to the gutter in which branch is arranged a nozzle q to whichwater under presure is supplied by means of the' pipe k2 fitted with avalve The branch 7c serves for filling the receiver z. with water.

On blowing off the boiler the circulation pump for the solution is firststopped, then the valves e, w and are opened so that the solutionfiowing ofi' passes through the tube system of the pre-heater t, Washesit and only then passes into the receiver L. The liquid fiowing throughthe pre-heater t which liquid is gradually becoming cleaner carries offwith it the impurities produced in the previous boiling operation andclinging to the walls of the tubes and leads it' away in one workingoperation with the blowing-off operation.

In the pipe f is disposed a three-way cock e to which a third waterpressure pipe k3 is connected. By means ofI this three-way cock, theboiler a can be filled with water independently of the pre-heater twhile the pre-heater can be washed independently of the boiler a.

Between the dome z' and the receive L may be provided a separate pipecorresponding to the pipe f in the construction shown in Fig. l, so thatin blowing-off the boiler a, the pre-heater may be cut off if it isunnecessary to Wash out thelatter.

The invention is applicable to high-pressure boiling apparatus of allkinds, even those provided with a central circulating pipe or those linwhich the .blow-off valve is disposed at the lower end of the boiler. Insuch latter circumstances the cleaning liquid is introduced into thebottom space of the boiler. The cleaning liquid may,even in boilersfitted with a blow-off valve arratus, comprising, introducing into theboiler at the same time as it is blown olf, a cool liquid diluent fordiluting and cooling the solution and sludge thereof which are to beblown ofi' from said boiler.

2. A method of cleaning high pressure boiling apparatus employingchemical solution for purifying or dissolving materials, said apparatushaving a preheater in conjunction with the boiler comprising,introducing into the boiler at the same time as it is blown ofi', a coolliquid diluent for diluting and cooling the solution and the sludgethereof which are to be blown off from said top 4cool liquid diluent fordiluting and cooling boiler, and simultaneously washing out thepreheater with the diluted solution issuing from the boiler.

3. The method as claimed in claim 1 comprising t-he additional step ofleading through the preheater the hot solution which is beingcontinuously diluted by liquid introduced preferably into the top partof said boiler and using such solution to wash out the preheater.

4. method of cleaning out pressure boiling apparatus which includesbesides the boiler, r preheater and a condenser, comprising introducinginto the boiler adjacent the at the time the boiler is blown off of athe solution and sludge thereof which are to be blown ofi1 from theboiler and at the same time washing out the preheater with I the hotsolution which is being continually diluted by the cool liquid diluent,said diluted solution being led into said condenser, mixed therein withcooling water and thereby still further diluted and then led olf intotheopen at a pressure approximately that of the atmosphere. i

5. Apparatus for purifying and charging or dissolving material throughthe agency of a hot chemical solution comprising a boiler having a dome,a perforated sieve plate within said boiler, a distributing pipeextending into said boiler for introducing a diluting liquid to saidboiler at the Vtime of blowing olf said boiler, said distributing pipebeing located in the dome above the perforated sieve plate, and acondenser through which is discharged the solution diluted by theintroduced liquid and freed from pressure above that of atmosphere.

6. Apparatus as claimed in claim 5v including a waste pipe connected tothe condenser, an injector intercalated to said waste pipe and means-fprfeedin water under pressure to said e]ector where y the solution fromsaid condenser is further diluted and,

drawn off.

7. Apparatus as claimed in claim 5 including a preheater interposed inthe path of the solution discharging from said boiler.

8. Apparatus for the purifying and dissolving of material through theagency of a hot chemical solution including a boiler, a blow off conduittherefor, a pipe for supplying liquid under pressure to said boiler atthe time of blowing ott' the boiler for diluting and cooling the liquidand sludge of the chemical solution, a preheater for the incomingsolution interposed in said blow off conduit, and a valved liquidpressure supply pipe communicating with said preheater, for flushing itindependently of the supplying of liquid under pressure to said boiler.

In testimony whereof I have signed my name to this specification.

i GUSTAV ULLMANN.

